This invention relates to new and useful improvements in metal melting furnaces particularly suited to the melting and separation of non-ferrous metals with embedded or attached ferrous components.
It is normally difficult to separate ferrous and non-ferrous components because of the relatively large volume of scrap which must be charged into a furnace which is then heated to the melting point of the material having the lowest melting point, whereupon this melted material is then poured from the furnace and the remainder of the scrap is removed from the furnace and the whole process is again repeated.
In this invention the final configuration of components is established by specific end use. However, the principles of operation remain the same; that is the invention raises the temperature of combustion of pyrolysis gas, by countercurrent heating of this gas and fresh air supply, by waste heat from a combustion chamber or chambers, such that the raised heating effect in the combustion chamber or chambers is significantly improved, while the exhaust gas heat loss is significantly minimized effecting improved thermal efficiency of operation, and by virtue of the temperatures obtained, broadens the scope of application of the device, even to pollution control afterburner service requirements, all functions essentially completed within the aforesaid configurations.
In the following, two specific but non-exclusive uses of the principle of operation receive, more or less, detailed explanation, subject of previous evidence namely, the application of the raised heating effect to melt and/or recover ferrous or non-ferrous metals from scrap utilizing mainly/only the thermal energy obtainable from combustible waste materials and again, the heating of pressurized water to above or below steam generation point for such a process and space heating functions.
Due to the relatively small percentage of low melting point material in normal scrap, the conventional system is expensive and time consuming particularly in view of the fact that, for example, melted aluminum must be removed immediately from contact with ferrous components in order to avoid contamination of the aluminum.
An example of such scrap that might be utilized and, in fact, often is utilized for this purpose, is pistons, piston rings and connecting rods together with the wrist pins attaching the pistons to the connecting rods.
The present invention overcomes these disadvantages by providing a melting furnace together with a source of burner fuel and comprising in combination a main body, means mounting said body for fore and aft tilting action, vertically situated dividing walls in said body defining the interior thereof into a melt chamber and a combustible gas producing pyrolysis chamber, a separate liquid metal holding chamber within said melt chamber, an exhaust gas cleaning chamber, means communicating between said melt chamber and said holding chamber adjacent the front upper side of said holding chamber, a burner assembly for said melt chamber and a further burner assembly for said holding chamber, means operatively connecting said combustible gas producing chamber with said first mentioned burner assembly on a selective basis, exhaust means for said furnace communicating between said melt chamber, said holding chamber and said exhaust gas cleaning chamber, a separate charging door for said melt chamber, and said holding chamber and a metal tapping hole in said holding chamber and selectively communicating through the wall of said main body.
Another aspect of the invention is to provide means whereby combustible waste can be heated to a predetermined temperature to produce combustible gases which can be used in assisting in the firing of the main melt chamber burner and the metal holding chamber burner thus reducing the cost of operation of the device by conventional fuels.
Still another aspect of the invention is to provide a device of the character herewithin described which is simple in construction, economical in manufacture and otherwise well suited to the purpose for which it is designed.
With the foregoing in view, and other advantages as will become apparent to those skilled in the art to which this invention relates as this specification proceeds, the invention is herein described by reference to the accompanying drawings forming a part hereof, which includes a description of the best mode known to the applicant and of the preferred typical embodiment of the principles of the present invention, in which: